Burrowing rodents, particularly gophers and some species of ground squirrels, are a serious problem for private homeowners and proprietors of many public commercial establishments, such as parks and golf courses and the like. Further, it is notoriously well known that there are many commercial solutions available to the general public for eradication and control of such pests. There are similarly many available traditional treatments, and much folklore associated with rodent and pest control in general. The inventor in the present case has caused a careful search to be made, and has presented, with this application, an Information Disclosure Statement (IDS) listing a number of patents and papers on the subject.
One primary method for controlling ground burrowing pests is to gas them with toxic smoke or a poisonous chemical agent. There are a variety of chemical or smoke producing implements and dispensing systems that are available on the market and purport to be successful in eradication gophers and like rodents. One such system is known to the inventor and described with reference to U.S. Pat. No. 6,247,265.
The method of Pat. No. 6,247,256involves a pest exterminating apparatus, comprising a tank for storing anhydrous ammonia and a supply line connected to the tank for dispensing the anhydrous ammonia from the tank. The supply line can be connected to a gas valve in a gas dispensing position or a liquid valve in a liquid dispensing position. An elongate wand having a flexible tube mounted on a free end is connected to a dispensing end of the supply line for insertion of the flexible tube into a gopher's burrow. A person holding the supply line is spaced from the ammonia being dispensed due to the elongate wand. In use, the person positions the tank adjacent a gopher's burrow and inserts the flexible tube into the burrow. A lever on the dispensing end of the supply line allows a valve to be opened for dispensing a portion of the ammonia into the burrow. The tank may then be relocated adjacent another burrow.
Two other chemical agent-dispensing methods for killing rodents in their burrows are known to the inventor and referenced herein as U.S. Pat. No. 5,548,921 and U.S. Pat. No. 5,588,252. The first of these listed methods involves a probe that is provided for the purpose of locating a portion of an underground burrow. Once the burrow is located, it is breached to an extent that a dry chlorine material may be physically placed therein. Once placement of the chlorine material is accomplished, water is poured over the material to cause a chemical reaction producing chlorine gas. The second of the listed methods involves using an automobile engine exhaust as a gas dispensing system delivering the gas through a delivery tube into a portion of an underground burrow causing death to the animals by asphyxiation due to carbon monoxide poisoning.
The above-described systems, while effective in varying degrees some of the time, fail to treat the problem thoroughly. It is known to the skilled artisan that ground burrowing animals, especially gophers, use certain methods to protect themselves and their young from being compromised in their burrows by predators or by flooding, or even by smoke generated from grass or forest fires. False tunnels are constructed, for example, as predator decoy tunnels that lead nowhere and are not used. Runs that are in use have special chambers elevated well above the flood level of the run so that the animals can escape water inundation. Additionally, when a gopher, for example, feels threatened by a predator, including a human attempting to compromise the run it will, very quickly, plug up certain key passages that give access to it's young and to itself and will construct new passages or re-open the old passages to these chambers when the danger has passed. These tactics can be used to render the heretofore-mentioned methods somewhat, if not entirely, in some cases, ineffective. Even if some adults are killed, often the young are spared and quickly take over.
What is clearly needed is an efficient delivery system for dispatching ground-burrowing pests that can be used to administer a first fast-acting agent that will render the pests immediately inactive for an initial period while a second dispersal of a lethal agent is administered.